Magnesium intake in relation to systemic inflammation, insulin resistance, and the incidence of diabetes

A 6-month follow-up study of the randomized controlled Ma-Pi macrobiotic dietary intervention (MADIAB trial) in type 2 diabetes

BACKGROUND

In the MADIAB trial (a 21-day randomized, controlled trial in patients with type 2 diabetes (T2D)), intervention with the Ma-Pi 2 macrobiotic diet resulted in significantly greater improvements in metabolic control compared with a standard recommended diet for patients with T2D. We report on a 6-month follow-up study, which investigated, whether these benefits extended beyond the 21-day intensive dietary intervention, in real-world conditions.

SUBJECTS

At the end of the MADIAB trial (baseline of this follow-up study), all participants continued their assigned diet (Ma-Pi or control) for 6 months. The Ma-Pi 2 group followed the Ma-Pi 4 diet during this follow-up study. Forty of the original 51 subjects (78.4%) participated in the follow-up (body mass index, 27-45 kg m(-2); age, 40-75 years). Primary outcome was percentage change from baseline in HbA1c; secondary outcomes were anthropometric data and lipid panel.

RESULTS

A significantly greater median percentage reduction was observed for HbA1c in the Ma-Pi group (-11.27% (95% confidence interval (CI): -10.17; -12.36)) compared with the control group (-5.88% (95% CI: -3.79; -7.98)) (P < 0.001). Total and low-density lipoprotein (LDL) cholesterol increased in both groups with no differences between groups (P=0.331 and P=0.082, respectively). After correcting for age and gender, the Ma-Pi diet was associated with a higher percentage reduction in HbA1c (95% CI: 2.56; 7.61) and body weight (95% CI: 0.40; 3.99), and a higher percentage increase in LDL cholesterol (95% CI: -1.52; -33.16). However, all participants' total and LDL cholesterol levels remained within recommended ranges (<200 mg dl(-1) and <100 mg dl(-1), respectively). The Ma-Pi diet group achieved the target median HbA1c value (<5.7% (39 mmol mol(-1))) at 6 months.

CONCLUSIONS

Both the Ma-Pi and control diets maintained their benefits beyond the 21-day intensive monitored intervention over a 6-month follow-up in real-world conditions. The Ma-Pi diet resulted in greater improvement in glycemic control.

New-Onset Diabetes After Kidney Transplantation and Pretransplant Hypomagnesemia

AIM

Hypomagnesemia is a frequent finding in kidney transplant patients and plays a causal role in insulin resistance and diabetes. The aim of this study was to investigate whether the pretransplant magnesium (Mg) level is a risk factor for the development of new-onset diabetes after kidney transplantation (NODAT) and the presence of relationship between pretransplant hypomagnesemia and the development period of NODAT.

METHODS

Four hundred and nineteen nondiabetic renal transplant recipients were evaluated retrospectively. The patients were divided into NODAT and non-NODAT groups. The time of diagnosis of patients with NODAT was divided into 0 to 3, 3 to 6, 6 to 12 months, and after 12 months. Patients' characteristics and pretransplant Mg levels in NODAT were compared with non-NODAT, and it was investigated whether pretransplant hypomagnesemia was a risk factor for the development of NODAT.

RESULTS

Totally 70 (16.6%) patients (36 female [F], mean age 51.7 ± 8.2 years) were diagnosed with NODAT. Three hundred and forty-nine patients (115 F, mean age 43.2 ± 12.5 years) did not have NODAT. Pretransplant mean Mg level was 1.97 ± 0.40 mg/dL in patients with NODAT, while it was 2.5 ± 0.45 mg/dL in non-NODAT patients (P < .001). Serum Mg level was found to be similar in subgroups according to the development period of NODAT (P = .07). When patients were stratified according to quartiles of Mg level, the frequency of NODAT was significantly higher in patients in the lower quartile (Mg < 2.1 mg/dL; P < .001). Older age, high body mass index, and low pretransplant serum Mg levels were established as risk factors for developing NODAT. According to the quartile of Mg level, the risk of developing NODAT was highest in the lowest quartile.

CONCLUSION

Pretransplant hypomagnesemia is an independent risk factor of NODAT. Therefore, it is necessary to closely monitor the Mg levels in the posttransplant period.

Association of Serum Magnesium Level with Odds of Prediabetes and Diabetes in a Southern Chinese Population: a Prospective Nested Case-Control Study

Although emerging clinical evidence supports that magnesium deficiency is a risk factor for the development of type 2 diabetes, there are sparse studies concerning the dynamic change of serum magnesium with the risk of diabetes and its early stages. In this nested case-control study, we performed a 75-g oral glucose tolerance test or a standardized steamed bread meal test in 178 subjects with incident glucose metabolism impairment (33 with type 2 diabetes and 145 with prediabetes) and 178 matched controls at baseline and at 3-year follow-up and determined the associations between baseline serum magnesium levels as well as changes in serum magnesium levels at follow-up and odds of prediabetes and diabetes. After adjusting for potential confounders, the odds ratios of risk for prediabetes and type 2 diabetes in the highest quartile of serum magnesium levels were 0.22 (95 % confidence intervals [CI] 0.10-0.49; p for trend <0.001) and 0.02 (95 % CI 0.00-0.29; p for trend = 0.009), respectively, as compared with the lowest quartile. In addition, a significant decline in the serum magnesium level was detected in type 2 diabetes cases (p = 0.015) at 3 years as compared with at baseline. These results suggest that a low magnesium level is an independent risk factor for prediabetes and type 2 diabetes, and that the reduction of serum magnesium is associated with type 2 diabetes in a southern Chinese population.

A systematic review and meta-analysis of randomized controlled trials on the effects of magnesium supplementation on insulin sensitivity and glucose control

A systematic review and meta-analysis was conducted to evaluate the effect of oral magnesium supplementation on insulin sensitivity and glucose control in both diabetic and non-diabetic individuals. PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases were searched (from inception to November 25, 2015) to identify RCTs evaluating the effect of magnesium on insulin sensitivity and glucose control. A random-effects model and generic inverse variance method were used to compensate for the heterogeneity of studies. Publication bias, sensitivity analysis, and meta-regression assessments were conducted using standard methods. The impact of magnesium supplementation on plasma concentrations of glucose, glycated hemoglobin (HbA1c), insulin, and HOMA-IR index was assessed in 22, 14, 12 and 10 treatment arms, respectively. A significant effect of magnesium supplementation was observed on HOMA-IR index (WMD: -0.67, 95% CI: -1.20, -0.14, p=0.013) but not on plasma glucose (WMD: -0.20mmol/L, 95% CI: -0.45, 0.05, p=0.119), HbA1c (WMD: 0.018mmol/L, 95% CI: -0.10, 0.13, p=0.756), and insulin (WMD: -2.22mmol/L, 95% CI: -9.62, 5.17, p=0.556). A subgroup analysis comparing magnesium supplementation durations of <4 months versus ≥4 months, exhibited a significant difference for fasting glucose concentrations (p<0.001) and HOMA-IR (p=0.001) in favor of the latter subgroup. Magnesium supplementation for ≥4 months significantly improves the HOMA-IR index and fasting glucose, in both diabetic and non-diabetic subjects. The present findings suggest that magnesium may be a beneficial supplement in glucose metabolic disorders.

Serum magnesium is inversely associated with coronary artery calcification in the Genetics of Atherosclerotic Disease (GEA) study

Background

Serum magnesium is inversely associated to coronary artery calcification (CAC) in patients with chronic kidney disease. There is little information on this association in a general healthy population.

Objective

The aim of this study was to examine the cross-sectional association of serum magnesium levels with CAC.

Methods

We included 1276 Mexican-mestizo subjects (50 % women), aged 30–75 years, free of symptomatic cardiovascular disease. CAC was quantified by multidetector computed tomography using the method described by Agatston. Cross-sectional associations of serum magnesium with cardiometabolic factors and subclinical atherosclerosis defined as a CAC score > 0, were examined in logistic regression models adjusted for age, sex, education, smoking status, body mass index, systolic blood pressure, physical activity, elevated abdominal visceral tissue, fasting insulin and glucose, alcohol consumption, menopausal status (women only), low (LDL-C) and high density lipoprotein cholesterol (HDL-C), triglycerides, diuretic use, type 2 diabetes mellitus (DM2), and family history of DM2.

Results

After full adjustment, subjects in the highest quartile of serum magnesium had 48 % lower odds of hypertension (p = 0.028), 69 % lower odds of DM2 (p = 0.003), and 42 % lower odds of CAC score > 0 (p = 0.016) compared to those with the lowest serum magnesium. The analyses also showed that a 0.17 mg/dL (1SD) increment in serum magnesium was independently associated with 16 % lower CAC (OR 0.84, 95 % CI 0.724–0.986).

Conclusions

In a sample of Mexican-mestizo subjects, low serum magnesium was independently associated to higher prevalence not only of hypertension and DM2, but also to coronary artery calcification, which is a marker of atherosclerosis and a predictor of cardiovascular morbidity and mortality.

Effect of magnesium sulfate and thyroxine on inflammatory markers in a rat model of hypothyroidism

Inflammation is a major risk factor for cardiovascular complications. Magnesium sulfate (MgSO4) has anti-inflammatory actions. Therefore we investigated the effects of levothyroxine and MgSO4 on inflammatory markers as C-reactive protein (CRP), interleukin-6, tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in hypothyroid rats. Sixty male rats were divided into 6 groups; normal, normal + MgSO4, hypothyroidism, hypothyroidism + levothyroxine, hypothyroidism + MgSO4, and hypothyroidism + levothyroxine + MgSO4. Thyroxine, triiodothyronine, and thyroid-stimulating hormone (TSH), CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 were measured in all rats. Hypothyroidism significantly increased TSH, CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 and decreased triiodothronine and thyroxine. Treatment of hypothyroid rats with levothyroxine or MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1. Combined therapy of hypothyroid rats with levothyroxine and MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 compared with hypothyroid rats either untreated or treated with levothyroxine or MgSO4. This study demonstrates that hypothyroid rats have chronic low grade inflammation, which may account for increased risk of cardiovascular diseases. Combined levothyroxine and MgSO4 is better than levothyroxine or MgSO4 alone in alleviating the chronic low grade inflammatory status and therefore reducing the risk of cardiovascular diseases in hypothyroid animals.

Impact of Nutrition on Cerebral Circulation and Cognition in the Metabolic Syndrome

The increasing prevalence of Metabolic Syndrome (MetS), defined as the clustering of abdominal obesity, dyslipidemia, hypertension, and hyperglycemia, appears to be driving the global epidemics cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Nutrition has a major impact on MetS and plays an important role in the prevention, development, and treatment of its features. Structural and functional alterations in the vasculature, associated with MetS, might form the link between MetS and the increased risk of developing CVD and T2DM. Not only does the peripheral vasculature seem to be affected, but the syndrome has a profound impact on the cerebral circulation and thence brain structure as well. Furthermore, strong associations are shown with stroke, cognitive impairment, and dementia. In this review the impact of nutrition on the individual components of MetS, the effects of MetS on peripheral and cerebral vasculature, and its consequences for brain structure and function will be discussed.

Magnesium in Prevention and Therapy

Magnesium is the fourth most abundant mineral in the body. It has been recognized as a cofactor for more than 300 enzymatic reactions, where it is crucial for adenosine triphosphate (ATP) metabolism. Magnesium is required for DNA and RNA synthesis, reproduction, and protein synthesis. Moreover, magnesium is essential for the regulation of muscular contraction, blood pressure, insulin metabolism, cardiac excitability, vasomotor tone, nerve transmission and neuromuscular conduction. Imbalances in magnesium status—primarily hypomagnesemia as it is seen more common than hypermagnesemia—might result in unwanted neuromuscular, cardiac or nervous disorders. Based on magnesium’s many functions within the human body, it plays an important role in prevention and treatment of many diseases. Low levels of magnesium have been associated with a number of chronic diseases, such as Alzheimer’s disease, insulin resistance and type-2 diabetes mellitus, hypertension, cardiovascular disease (e.g., stroke), migraine headaches, and attention deficit hyperactivity disorder (ADHD).

Magnesium and type 2 diabetes

Type 2 diabetes is frequently associated with both extracellular and intracellular magnesium (Mg) deficits. A chronic latent Mg deficit or an overt clinical hypomagnesemia is common in patients with type 2 diabetes, especially in those with poorly controlled glycemic profiles. Insulin and glucose are important regulators of Mg metabolism. Intracellular Mg plays a key role in regulating insulin action, insulin-mediated-glucose-uptake and vascular tone. Reduced intracellular Mg concentrations result in a defective tyrosine-kinase activity, postreceptorial impairment in insulin action and worsening of insulin resistance in diabetic patients. A low Mg intake and an increased Mg urinary loss appear the most important mechanisms that may favor Mg depletion in patients with type 2 diabetes. Low dietary Mg intake has been related to the development of type 2 diabetes and metabolic syndrome. Benefits of Mg supplementation on metabolic profiles in diabetic patients have been found in most, but not all clinical studies and larger prospective studies are needed to support the potential role of dietary Mg supplementation as a possible public health strategy in diabetes risk. The aim of this review is to revise current evidence on the mechanisms of Mg deficiency in diabetes and on the possible role of Mg supplementation in the prevention and management of the disease.

In vitro degradation of pure Mg in response to glucose

Magnesium and its alloys are promising biodegradable biomaterials but are still challenging to be used in person with high levels of blood glucose or diabetes. To date, the influence of glucose on magnesium degradation has not yet been elucidated, this issue requires more attention. Herein, we present pure Mg exhibiting different corrosion responses to saline and Hank’s solutions with different glucose contents, and the degradation mechanism of pure Mg in the saline solution with glucose in comparison with mannitol as a control. On one hand, the corrosion rate of pure Mg increases with the glucose concentration in saline solutions. Glucose rapidly transforms into gluconic acid, which attacks the oxides of the metal and decreases the pH of the solution; it also promotes the absorption of chloride ions on the Mg surface and consequently accelerates corrosion. On the other hand, better corrosion resistance is obtained with increasing glucose content in Hank’s solution due to the fact that glucose coordinates Ca²⁺ ions in Hank’s solution and thus improves the formation of Ca-P compounds on the pure Mg surface. This finding will open up new avenues for research on the biodegradation of bio-Mg materials in general, which could yield many new and interesting results.

Influence of dietary intake of fish oil, magnesium, and zinc on metabolic parameters among individuals tested for diabetes

OBJECTIVE

The aim of this study was to assess the significance and degree of correlation between the intake of fish oil, magnesium (Mg), and zinc (Zn) and metabolic parameters.

METHODS

Correlation coefficients among nutrient intake and physical and laboratory parameters were determined using Spearman's rho (ρ) test or a multiple regression model among Japanese individuals (male:female, 37:66; median age, 55 y) who completed a semiquantitative food questionnaire and underwent testing for diabetes. Individuals with diabetes were excluded.

RESULTS

Spearman's test revealed several weak but significant correlations between intake of fish oil including ω-3 polyunsaturated fatty acids (PUFAs) and various metabolic parameters. The test showed that Zn intake in women significantly correlated with reduced systolic blood pressure (SBP), alanine aminotransferase (ALT), γ-glutamyl transpeptidase (γ-GPT), and homeostasis model assessment-insulin resistance (HOMA-IR). Multivariate analysis revealed that intake of fish oil, eicosapentaenoic acid (EPA), and Zn was significantly associated with increased serum levels of high-density lipoprotein cholesterol (HDL-C; fish oil versus HDL-C, P = 0.0438; 95% confidence interval [CI], 0.0055-0.3724; EPA versus HDL-C, P = 0.0439; 95% CI, 0.0053-0.3724; Zn versus HDL-C, P = 0.0041; 95% CI, 0.0890-0.4609). Multivariate analysis revealed that ω-3 PUFAs were associated with decreased serum ALT levels (P = 0.0240; 95% CI, -5.000 to -0.0367) and that Zn correlated with SBP (P = 0.0239; 95% CI, -0.5149 to -0.0377) in women.

CONCLUSION

Intake of fish oil, Mg, and Zn was associated with some metabolic parameters. Abundant intake of fish oil including ω-3 PUFAs and Zn can exert antiarteriosclerotic effects through increasing serum levels of HDL-C. ω-3 PUFAs can reduce liver inflammation and Zn can reduce SBP in women.

Associations of serum Magnesium levels with diabetes mellitus and diabetic complications

BACKGROUND

Magnesium (Mg) deficiency is a common problem in diabetic patients. Deficiency of Mg may increase the incidence of diabetes mellitus (DM) and occurrence of diabetic complications. In this study, our aim was to evaluate an association between serum Mg level,  glycemic regulation, and diabetic complications.

MATERIAL-METHODS

In this retrospective study 673 diabetic patients were evaluated. According to Mg levels, the patients were divided into two groups; as normomagnesemic patients and hypomagnesemic patients.

RESULTS

Among the patients, 57.8% were men and 42.2% were women. Mean age was 55.6 years and the mean duration of diabetes was 81 ± 86.9 months. The mean glycosylated hemoglobin (HbA1c) was 9.0 ±2.4 % (4.5-18); mean magnesium level was 1.97 ± 0.25 (1.13 to 3.0) mg / dl.  There were 55 patients (8.2%) with diabetic retinopathy and 95 patients (14.1%) with diabetic neuropathy. Five hundred patients (74.3%)  had normoalbuminuria; 133 patients (19. 8%) had microalbuminuria (MA) and 40 patients (5.9%) had overt proteinuria. One hundred and seventy one patients (25.4%) had HbA1c levels equal or below 7%; and 502 patients (74.6%) had HbA1c levels above 7%. There was no statistical difference in age or duration of diabetes between the groups formed according to Mg levels. Although there were no differences between the groups for retinopathy and neuropathy, MA was more common in hypomagnesemic patients (p =0.004). HbA1c levels did not differ between the groups (p =0.243). However there was a weak negative correlation between serum Mg and HbA1c levels (r =-0.110, p =0.004) and also between serum Mg and urine protein level  (r =-0.127, p =0.018).

CONCLUSION

Mg depletion is a common problem in patients with DM. It affects both glycemic regulation and the occurence of complications. Also, poor glycemic regulation affects serum Mg levels. Hippokratia 2015; 19 (2):153-157.

Hypomagnesemia, chronic kidney disease and cardiovascular mortality: pronounced association but unproven causation

Magnesium is as an essential metal implicated in numerous physiological functions of human cells. The kidney plays a crucial role in magnesium homeostasis. In advanced chronic kidney disease, serum magnesium levels are increased. Data from experimental and observational studies suggest that low levels of magnesium are associated with several factors, such as insulin resistance, diabetes, oxidative stress, hypertension, atherosclerosis, and inflammation which are implicated in the progression of chronic kidney disease. Moreover, low levels of magnesium have been correlated with cardiovascular disease and all-cause mortality in end-stage renal disease patients. Hypomagnesemia has also been associated with poorer renal allograft and transplant recipients' outcomes. The causality of these relationships has not been completely elucidated. A thorough review of the current literature indicates that low magnesium levels in dialysis patients may reflect a poorer nutritional status and/or are the result of systemic inflammation. Further studies in chronic kidney disease and dialysis patients are needed in order to clarify the causality of these associations.

Protective effect of magnesium on renal function in STZ-induced diabetic rats

BACKGROUND

Diabetic nephropathy is a serious complication of T1D (type one diabetes mellitus). Persistent hyperglycemia and subsequent hypomagnesemia is believed to develop kidney damage by activation of oxidative stress. We conducted this study to investigate the renoprotective effect of magnesium sulfate (MgSO4) on renal histopathology and oxidative stress in diabetic rats.

METHODS

The study included 70 male rats. The animals were divided into seven groups: control (CRL), control receiving MgSO4 (CRL + Mg1 & CRL + Mg8), diabetic (DM1 & DM8) and diabetic receiving MgSO4 (DM + Mg1 & DM + Mg8). Rats were given 20 mg/kg (i.p) Streptozocin (STZ) for 5 consecutive days in (MLD) multiple low doses to induce T1D. At day 10 treatment groups were received MgSO4 (10 g/l) in drinking water, for 1 or 8 weeks. The blood glucose, BUN and creatinine levels were measured. Renal tissue levels of malondialdehyde (MDA) were measured by thiobarbituric acid (TBA) method to evaluate the oxidative stress. Renal histopathology was done using H & E staining method.

RESULTS

Treatment with MgSO4 significantly decreased the blood glucose in DM + Mg1 and DM + Mg8 groups as compared with DM1 and DM8. Magnesium treatment also decreased serum BUN and tissue level of MDA significantly in both short and long term treatment. The body weight loss and kidney weight to body weight ratio was improved by MgSO4. Histological results showed there were no differences between DM and DM + Mg groups.

CONCLUSION

Our findings showed that diabetic nephropathy is associated with high blood glucose level and oxidative stress (significant increase in MDA level). The renal dysfunction and oxidative stress can be improved by magnesium sulfate administration. It is suggested that protection against development of diabetic nephropathy by MgSO4 treatment involves changes in the blood glucose and oxidative stress.

Dietary magnesium intake and risk of cancer: a meta-analysis of epidemiologic studies

The aim of this study was to investigate the association between dietary magnesium and the risk of overall cancer using a meta-analysis. We searched PubMed, SCOPUS, and the Cochrane Review through November 2012. All the articles searched were independently reviewed by 3 authors based on predetermined selection criterion. A total of 13 epidemiologic studies, 6 case-control studies, and 7 prospective cohort studies involving 1,236,004 participants were included in the final analysis. When all studies were pooled, the relative risk (RR) of overall cancer for the highest level of dietary magnesium intake was 0.801 [95% confidence interval (CI): 0.664-0.966) compared with the lowest level of dietary magnesium intake. In subgroup meta-analyses by study design, there was a significant inverse association between dietary magnesium and the risk of cancer in case-control studies (RR = 0.663, 95% CI: 0.475-0.925), whereas there was no significant association in prospective cohort studies (RR = 0.888, 95% CI: 0.745-1.060). Furthermore, there was a significant preventive effect of dietary magnesium for colorectal cancer (RR = 0.775, 95% CI: 0.655-0.919), but not for other cancer. Our meta-analysis showed that higher dietary magnesium intake seems to have a protective effect for cancer, especially colorectal cancer and in females.

Serum ionized magnesium in diabetic older persons

OBJECTIVE

Several alterations of magnesium metabolism have been associated with type 2 diabetes pathophysiology, a condition particularly frequent in older persons. We aimed to evaluate serum total (Mg-tot) and serum ionized magnesium (Mg-ion) in older persons with type 2 diabetes in order to explore clinically applicable methods for the detection of magnesium deficit.

MATERIAL/METHODS

Mg-tot and Mg-ion were measured in 105 fasting subjects with type 2 diabetes (mean age: 71.1±0.8 years; M/F: 45/60) and in 100 age-matched non-diabetic control persons (mean age: 72.2±0.8 years; M/F: 42/58).

RESULTS

Mg-ion concentrations were significantly lower in diabetic persons compared with controls (0.49±0.05 mmol/L vs. 0.55±0.05 mmol/L; p<0.001). Mg-tot was also slightly but significantly lower in diabetic patients (0.82±0.007 mmol/L vs. 0.84±0.006 mmol/L; p<0.05). There was an almost complete overlap in the values of Mg-tot in older diabetic patients and controls; conversely, 44.8% of diabetic patients had Mg-ion values below 0.47 mmol/L, while none of the controls did. After adjustment for age, sex, BMI, and triglycerides, Mg-tot was significantly associated with FBG in all the participants (p<0.05) and Mg-ion was significantly associated with FBG in all the participants (p<0.01) and with HbA1c in diabetic participants (p<0.001).

CONCLUSIONS

Alterations of magnesium serum concentrations are common in type 2 diabetic older adults; Mg-ion evaluation may help to identify subclinical magnesium depletion (i.e. in patients with normal Mg-tot); the close independent associations of Mg-tot and Mg-ion with FBG and with HbA1c reinforce the possible link between magnesium homeostasis and altered glucose metabolism.

Coffee and green tea consumption is associated with insulin resistance in Japanese adults

OBJECTIVE

Higher coffee and green tea consumption has been suggested to decrease risk of type 2 diabetes, but their roles in insulin resistance (IR) and insulin secretion remain unclear. This study examined the association between habitual consumption of these beverages and markers of glucose metabolism in a Japanese working population.

MATERIALS/METHODS

Participants were 1440 Japanese employees (1151 men and 289 women) aged 18-69years. Consumption of coffee and green tea was ascertained via a validated brief diet history questionnaire. Multilevel linear regression was used to estimate means (95% confidence intervals) of fasting insulin, fasting plasma glucose, homeostatic model assessment of IR (HOMA-IR), homeostatic model assessment of β-cell function (HOMA-β) and glycated hemoglobin (HbA1c) with adjustment for potential confounding variables.

RESULTS

Coffee consumption was significantly, inversely associated with HOMA-IR (P for trend=0.03), and the association appeared to be confined to overweight subjects (BMI≥25kg/m(2)) (P for trend=0.01, P for interaction=0.08). Unexpectedly, green tea consumption was positively associated with HOMA-IR (P for trend=0.02), though there was no dose-response relationship among daily consumers of green tea. Neither coffee nor green tea consumption was associated with HOMA-β and HbA1c.

CONCLUSIONS

Our findings indicate that coffee consumption may be associated with decreased IR, but not with insulin secretion. The positive association between green tea consumption and IR warrants further investigation.

Ma-Pi 2 macrobiotic diet and type 2 diabetes mellitus: pooled analysis of short-term intervention studies

The macrobiotic, Ma-Pi 2 diet (12% protein, 18% fat and 70% carbohydrate), has shown benefit in adults with type 2 diabetes mellitus (T2DM). This pooled analysis aims to confirm results from four, 21-day intervention studies with the Ma-Pi 2 diet, carried out in Cuba, China, Ghana and Italy. Baseline and end of study biochemical, body composition and blood pressure data, were compared using multivariate statistical methods and assessment of the Cohen effect size (d). Results showed that all measured indicators demonstrated significant changes (p < 0.001); most of them with a very high (d ≥ 1.30), or high (d = 0.80-1.29) effect size. The global effect size of the diet was Italy (1.96), China (1.79), Cuba (1.38) and Ghana (0.98). The magnitude of the individual effect on each variable by country, and the global effect by country, was independent of the sample size (p > 0.05). Similarly, glycemia and glycemic profiles in all four studies were independent of the sample size (p = 0.237). The Ma-Pi diet 2 significantly reduced glycemia, serum lipids, uremia and cardiovascular risk in adults with T2DM. These results suggest that the Ma-Pi 2 diet could be a valid alternative treatment for patients with T2DM and point to the need for further clinical studies. Mechanisms related to its benefits as a functional diet are discussed.

Low serum magnesium levels and diabetic foot ulcers

Objective: Magnesium plays an important role in glucose homeostasis and insulin sensitivity. The aim of this study was to investigate the association between serum magnesium levels and diabetic foot ulcers.

Methods: A total of 147 subjects were included in this study. The participants were divided into three groups, including a study group of 49 patients with diabetes and foot ulcers, a control group of patients with diabetes without foot ulcers and a control group of 49 healthy subjects. Measurements and comparisons were made of the participants’ magnesium levels, HBA1C percentages, serum fasting glucose levels, creatinine levels and serum lipid levels for all groups. MedCalc version 12.0 (MedCalc, Turkey) was used for the statistical analysis.

Results: The groups were similar in terms of age and sex (p=0.116 and 0.897, respectively). The magnesium levels of the patients with diabetes and foot ulcers were lower than those in the patients with diabetes without foot ulcers and the healthy subjects (p<0.001). There was a strong relationship between the serum magnesium levels and the incidence of diabetic foot ulcers (OR 5.9, Cl 95% 2.7-12.6, p<0.001).

Conclusions: A low serum magnesium level is associated with diabetic foot ulcers. Therefore, the magnesium levels should be controlled in patients with diabetes (with or without foot ulcers) and magnesium supplementation can be a complimentary treatment in such cases.

Dietary magnesium intake is inversely associated with serum C-reactive protein levels: meta-analysis and systematic review

BACKGROUND/OBJECTIVES

The aim of this study was to quantitatively summarize the association of dietary magnesium (Mg) intake with serum C-reactive protein (CRP) levels in the general population.

SUBJECTS/METHODS

Observational and experimental studies through February 2013 were reviewed in PubMed and EMBASE. Additional information was retrieved through Google or hand search of related reference lists. The main outcome is either adjusted geometric mean of CRP or odds ratio (OR) of having serum CRP ≥ 3 mg/l. Meta-regression was used to determine the linear association of dietary Mg intake and adjusted geometric means of CRP levels. A fixed-effects model was used to pool ORs of interest, comparing those in the lowest with those in the highest group of dietary Mg intake.

RESULTS

A data set derived from seven cross-sectional studies including 32,918 participants was quantitatively assessed. A weighted inverse association between Mg intake and serum CRP levels was observed (β-coefficient: -0.0028; 95% confidence interval (CI), -0.0043 to -0.0013; P(trend) = 0.001) from four cross-sectional studies. The pooled OR (95% CI) of having CRP ≥ 3 mg/l was 1.49 (1.18-1.89) on comparing the lowest to the highest group of Mg intake from three studies with the data available. Qualitative assessment among five intervention studies also showed a potential beneficial effect of Mg intake on serum CRP levels.

CONCLUSIONS

This meta-analysis and systematic review indicates that dietary Mg intake is significantly and inversely associated with serum CRP levels. The potential beneficial effect of Mg intake on chronic diseases may be, at least in part, explained by inhibiting inflammation.

Higher magnesium intake reduces risk of impaired glucose and insulin metabolism and progression from prediabetes to diabetes in middle-aged americans

OBJECTIVE

To assess 7-year associations between magnesium intake and incident prediabetes and/or insulin resistance (IR), and progression from these states to type 2 diabetes.

RESEARCH DESIGN AND METHODS

In 2,582 community-dwelling participants 26-81 years old at baseline, magnesium intake and risk of incident "metabolic impairment," defined as impaired fasting glucose (FG) (≥5.6 to <7.0 mmol/L), impaired glucose tolerance (2-h postload glucose ≥7.8 to <11.1 mmol/L), IR, or hyperinsulinemia (≥90th percentile of homeostasis model assessment of IR or fasting insulin, respectively), was estimated among those with normal baseline status, and risk of incident diabetes was estimated among those with baseline metabolic impairment. In participants without incident diabetes, we examined magnesium intake in relation to 7-year changes in fasting and postload glucose and insulin, IR, and insulin sensitivity.

RESULTS

After adjusting for age, sex, and energy intake, compared with those with the lowest magnesium intake, those with the highest intake had 37% lower risk of incident metabolic impairment (P trend = 0.02), and in those with baseline metabolic impairment, higher intake was associated with 32% lower risk of incident diabetes (P trend = 0.05). In the combined population, the risk in those with the highest intake was 53% (P trend = 0.0004) of those with the lowest intake. Adjusting for risk factors and dietary fiber attenuated associations in the baseline normal population but did not substantially affect associations in the metabolically impaired. Higher magnesium intake tended to associate with lower follow-up FG and IR, but not fasting insulin, postload values, or insulin sensitivity.

CONCLUSIONS

Magnesium intake may be particularly beneficial in offsetting risk of developing diabetes among those at high risk. Magnesium's long-term associations with non-steady-state (dynamic) measures deserve further research.

Serum magnesium level is associated with type 2 diabetes in women with a history of gestational diabetes mellitus: the Korea National Diabetes Program study

Gestational diabetes mellitus (GDM) is a strong predictor of postpartum prediabetes and transition to overt type 2 diabetes (T2DM). Although many reports indicate that low magnesium is correlated with deteriorated glucose tolerance, the association between postpartum serum magnesium level and the risk for T2DM in women with a history of GDM has not been evaluated. We analyzed postpartum serum magnesium levels and development of prediabetes and T2DM in women with prior GDM according to American Diabetes Association (ADA) criteria using the Korean National Diabetes Program (KNDP) GDM cohort. During a mean follow-up of 15.6 ± 2.0 months after screening, 116 women were divided into three groups according to glucose tolerance status. Ultimately, eight patients (6.9%) were diagnosed with T2DM, 59 patients (50.9%) with prediabetes, and 49 patients (42.2%) with normal glucose tolerance (NGT) after follow-up. The T2DM group had the lowest serum magnesium level (0.65 [0.63-0.68] mM/L) in the postpartum period, but there was no significant difference between the prediabetes group (0.70 [0.65-0.70] mM/L) and the NGT group (0.70 [0.65-0.70] mM/L) (P=0.073) Multiple logistic regression analysis showed that postpartum HOMA-IR was a significant predictor of both prediabetes and T2DM. Moreover, we found that postpartum serum magnesium level was also a possible predictor for T2DM development. Serum magnesium level in the postpartum period may be a possible predictor for T2DM development in women with a history of GDM.

Dietary magnesium and genetic interactions in diabetes and related risk factors: a brief overview of current knowledge

Nutritional genomics has exploded in the last decade, yielding insights—both nutrigenomic and nutrigenetic—into the physiology of dietary interactions and our genes. Among these are insights into the regulation of magnesium transport and homeostasis and mechanisms underlying magnesium’s role in insulin and glucose handling. Recent observational evidence has attempted to examine some promising research avenues on interaction between genetics and dietary magnesium in relation to diabetes and diabetes risk factors. This brief review summarizes the recent evidence on dietary magnesium’s role in diabetes and related traits in the presence of underlying genetic risk, and discusses future potential research directions.

The role of iron-induced fibrin in the pathogenesis of Alzheimer's disease and the protective role of magnesium

Amyloid hypothesis of Alzheimer's disease (AD) has recently been challenged by the increasing evidence for the role of vascular and hemostatic components that impair oxygen delivery to the brain. One such component is fibrin clots, which, when they become resistant to thrombolysis, can cause chronic inflammation. It is not known, however, why some cerebral thrombi are resistant to the fibrinolytic degradation, whereas fibrin clots formed at the site of vessel wall injuries are completely, although gradually, removed to ensure proper wound healing. This phenomenon can now be explained in terms of the iron-induced free radicals that generate fibrin-like polymers remarkably resistant to the proteolytic degradation. It should be noted that similar insoluble deposits are present in AD brains in the form of aggregates with Abeta peptides that are resistant to fibrinolytic degradation. In addition, iron-induced fibrin fibers can irreversibly trap red blood cells (RBCs) and in this way obstruct oxygen delivery to the brain and induce chronic hypoxia that may contribute to AD. The RBC-fibrin aggregates can be disaggregated by magnesium ions and can also be prevented by certain polyphenols that are known to have beneficial effects in AD. In conclusion, we argue that AD can be prevented by: (1) limiting the dietary supply of trivalent iron contained in red and processed meat; (2) increasing the intake of chlorophyll-derived magnesium; and (3) consumption of foods rich in polyphenolic substances and certain aliphatic and aromatic unsaturated compounds. These dietary components are present in the Mediterranean diet known to be associated with the lower incidence of AD and other degenerative diseases.

Serum magnesium in the metabolically-obese normal-weight and healthy-obese subjects

BACKGROUND

Given that hypomagnesemia is related with hyperglycemia, hypertension, hypertriglyceridemia, and insulin resistance, the objective of this study was to determine whether serum magnesium levels are associated with the metabolically obese normal weight (MONW) and the metabolically healthy obese (MHO) phenotypes.

METHODS

Population-based cross-sectional study that enrolled 427 subjects, men and non-pregnant women aged 20 to 65years, to participate in the study. Subjects were allocated into groups with and without obesity; among non-obese individuals, the subgroup of MONW subjects was compared with a control group of healthy normal-weight individuals. Among obese individuals, the subgroup of MHO subjects was compared with a control group of obese subjects who exhibited at least one metabolic abnormality. In the absence of obesity, the presence of fasting hyperglycemia, insulin resistance, hypertriglyceridemia, and/or hypertension defined the presence of MONW phenotype. In the absence of hypertension, insulin resistance and metabolic abnormalities of fasting glucose and triglycerides levels, the phenotypically obese subjects were defined as MHO individuals.

RESULTS

The sex-adjusted prevalence of MONW and MHO phenotypes was 40.8% and 27.9%. The multivariate logistic regression model adjusted by family history of diabetes, age, body mass index, and waist-circumference, showed a positive association between hypomagnesemia and the MONW phenotype (OR 6.4; 95%CI 2.3-20.4) and negative relationship between serum magnesium and the MHO phenotype (OR 0.32; 95%CI 0.17-0.61).

CONCLUSIONS

Our results show that hypomagnesemia is positively associated with the presence of MONW phenotype, and the normomagnesemia negatively with the MHO phenotype.

Dietary magnesium intake improves insulin resistance among non-diabetic individuals with metabolic syndrome participating in a dietary trial

Many cross-sectional studies show an inverse association between dietary magnesium and insulin resistance, but few longitudinal studies examine the ability to meet the Recommended Dietary Allowance (RDA) for magnesium intake through food and its effect on insulin resistance among participants with metabolic syndrome (MetS). The dietary intervention study examined this question in 234 individuals with MetS. Magnesium intake was assessed using 24-h dietary recalls at baseline, 6, and 12 months. Fasting glucose and insulin levels were collected at each time point; and insulin resistance was estimated by the homeostasis model assessment (HOMA-IR). The relation between magnesium intake and HOMA-IR was assessed using linear mixed models adjusted for covariates. Baseline magnesium intake was 287 ± 93 mg/day (mean ± standard deviation), and HOMA-IR, fasting glucose and fasting insulin were 3.7 ± 3.5, 99 ± 13 mg/dL, and 15 ± 13 μU/mL, respectively. At baseline, 6-, and 12-months, 23.5%, 30.4%, and 27.7% met the RDA for magnesium. After multivariate adjustment, magnesium intake was inversely associated with metabolic biomarkers of insulin resistance (P < 0.01). Further, the likelihood of elevated HOMA-IR (>3.6) over time was 71% lower [odds ratio (OR): 0.29; 95% confidence interval (CI): 0.12, 0.72] in participants in the highest quartile of magnesium intake than those in the lowest quartile. For individuals meeting the RDA for magnesium, the multivariate-adjusted OR for high HOMA-IR over time was 0.37 (95% CI: 0.18, 0.77). These findings indicate that dietary magnesium intake is inadequate among non-diabetic individuals with MetS and suggest that increasing dietary magnesium to meet the RDA has a protective effect on insulin resistance.

Urinary and plasma magnesium and risk of ischemic heart disease

BACKGROUND

Previous studies on dietary magnesium and risk of ischemic heart disease (IHD) have yielded inconsistent results, in part because of a lack of direct measures of actual magnesium uptake. Urinary excretion of magnesium, an indicator of dietary magnesium uptake, might provide more consistent results.

OBJECTIVE

The objective was to investigate whether urinary magnesium excretion and plasma magnesium are associated with IHD risk.

DESIGN

We examined 7664 adult participants free of known cardiovascular disease in the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study-a prospective population-based cohort study. Urinary magnesium excretion was measured in 2 baseline 24-h urine collections.

RESULTS

Mean ± SD urinary magnesium excretion was 4.24 ± 1.65 mmol/24 h for men and 3.54 ± 1.40 mmol/24 h for women. During a median follow-up of 10.5 y (IQR: 9.9-10.8 y), 462 fatal and nonfatal IHD events occurred. After multivariable adjustment, urinary magnesium excretion had a nonlinear relation with IHD risk (P-curvature = 0.01). The lowest sex-specific quintile (men: <2.93 mmol/24 h; women: <2.45 mmol/24 h) had an increased risk of fatal and nonfatal IHD (multivariable HR: 1.60; 95% CI: 1.28, 2.00) compared with the upper 4 quintiles of urinary magnesium excretion. A similar increase in risk of the lowest quintile was observed for mortality related to IHD (HR: 1.70; 95% CI: 1.10, 2.61). No associations were observed between circulating magnesium and risk of IHD.

CONCLUSIONS

Low urinary magnesium excretion was independently associated with a higher risk of IHD incidence. An increased dietary intake of magnesium, particularly in those with the lowest urinary magnesium, could reduce the risk of IHD.

Changes in mineral status are associated with improvements in insulin sensitivity in obese patients following L-arginine supplementation

PURPOSE

The aim of this study is to evaluate the long-term influence of L-arginine intake on mineral concentration in patients with obesity and to assess the changes in lipid serum levels, fat content, and insulin resistance that result.

METHODS

A randomized double-blind placebo-controlled study was conducted. 88 obese patients were randomly assigned to receive either 9 g of L-arginine or placebo daily, for 6 months. At baseline and after 6 months, selected anthropometrical measurements and blood biochemical analyses were performed and mineral levels were assessed. To assess insulin sensitivity, the gold-standard euglycemic clamp methodology was used.

RESULTS

We found that 6 months of L-arginine supplementation resulted in significant increases in insulin sensitivity (Δ1.1 mg/kg/min, P < 0.01) and zinc levels (Δ1.5 μmol/L, P < 0.001). Moreover, a positive correlation between the change in zinc concentration in serum and the change in insulin sensitivity was observed (R = 0.80, P < 0.01). In the group of patients treated with L-arginine, a negative correlation between the change in zinc concentration in serum and the change in body fat content was noted (R = -0.38, P < 0.05).

CONCLUSIONS

L-Arginine supplementation affects zinc status in obese patients. One beneficial influence is related to the improvements in insulin sensitivity.

Whole grains, type 2 diabetes, coronary heart disease, and hypertension: links to the aleurone preferred over indigestible fiber

Higher whole grain cereal intakes are associated with substantially lower risks of type 2 diabetes, coronary heart disease, and hypertension. These reduced risks have been established in large prospective studies that now include millions of person-years of follow-up. We analyze the results of 11 major prospective studies to provide recommendations about whole grain consumption. The following review establishes the amount of whole grains that should ideally be consumed based on prospective evidence; defines the nature of whole grains; identifies that the whole grain evidence is robust and not due to confounding; and provides a detailed assessment of several potential mechanisms for the effect of whole grains on health. We draw the following conclusions. Firstly, to maintain health, 40 grams or more of whole grains should be consumed daily. This is about a bowl of whole grain breakfast cereal daily, but 80% of the population does not achieve this. Secondly, aleurone in bran is a critical grain component generally overlooked in favor of indigestible fiber. Live aleurone cells constitute 50% of millers' bran. They store minerals, protein, and the antioxidant ferulic acid, and are clearly more than just indigestible fiber. Finally, we suggest potential roles for magnesium, zinc, and ferulic acid in the development of chronic disease. If the results of prospective studies were applied to the life-style practices of modern societies there exists the potential for enormous personal health and public financial benefits.

Serum free fatty acid levels in PCOS patients treated with glucophage, magnesium oxide and spironolactone

To assess the effect of glucophage, magnesium oxide and spironolactone in altering free fatty acids (FFAs), 36 PCOS women were randomly divided into three groups. Group 1 (n = 14) was treated with 500 mg glucophage po bid, group 2 (n = 10) was treated with 400 mg magnesium oxide po bid and group 3 (n = 12) was treated with 50 mg spironolactone po bid for 12 weeks. A glucose tolerance test with 75 g glucose load was performed before and after treatment, collecting blood at 0, 1 and 2 h for insulin, glucose, FFA and aldosterone. Amount of FFA before and after treatment were compared by repeated measure ANOVA and represented as area under the curve. FFA levels before treatment were 0.83 ± 0.23, 0.77 ± 0.15 and 0.85 ± 0.28 and after treatment were 0.77 ± 0.48, 0.71 ± 0.18 and 0.66 ± 0.25 for glucophage, magnesium oxide and spironolactone-treated patients, respectively. The FFA levels were unchanged in the groups treated with glucophage and magnesium oxide but were significantly (p < 0.03) decreased in the group treated with spironolactone. Since FFAs are known to be involved in the development of insulin resistance, these results suggest that spironolactone may be useful for lowering insulin resistance in PCOS patients.

High dietary magnesium intake is associated with low insulin resistance in the Newfoundland population

Background

Magnesium plays a role in glucose and insulin homeostasis and evidence suggests that magnesium intake is associated with insulin resistance (IR). However, data is inconsistent and most studies have not adequately controlled for critical confounding factors.

Objective

The study investigated the association between magnesium intake and IR in normal-weight (NW), overweight (OW) and obese (OB) along with pre- and post- menopausal women.

Design

A total of 2295 subjects (590 men and 1705 women) were recruited from the CODING study. Dietary magnesium intake was computed from the Willett Food Frequency Questionnaire (FFQ). Adiposity (NW, OW and OB) was classified by body fat percentage (%BF) measured by Dual-energy X-ray absorptiometry according to the Bray criteria. Multiple regression analyses were used to test adiposity-specific associations of dietary magnesium intake on insulin resistance adjusting for caloric intake, physical activity, medication use and menopausal status.

Results

Subjects with the highest intakes of dietary magnesium had the lowest levels of circulating insulin, HOMA-IR, and HOMA-ß and subjects with the lowest intake of dietary magnesium had the highest levels of these measures, suggesting a dose effect. Multiple regression analysis revealed a strong inverse association between dietary magnesium with IR. In addition, adiposity and menopausal status were found to be critical factors revealing that the association between dietary magnesium and IR was stronger in OW and OB along with Pre-menopausal women.

Conclusion

The results of this study indicate that higher dietary magnesium intake is strongly associated with the attenuation of insulin resistance and is more beneficial for overweight and obese individuals in the general population and pre-menopausal women. Moreover, the inverse correlation between insulin resistance and dietary magnesium intake is stronger when adjusting for %BF than BMI.

Higher magnesium intake is associated with lower fasting glucose and insulin, with no evidence of interaction with select genetic loci, in a meta-analysis of 15 CHARGE Consortium Studies

Favorable associations between magnesium intake and glycemic traits, such as fasting glucose and insulin, are observed in observational and clinical studies, but whether genetic variation affects these associations is largely unknown. We hypothesized that single nucleotide polymorphisms (SNPs) associated with either glycemic traits or magnesium metabolism affect the association between magnesium intake and fasting glucose and insulin. Fifteen studies from the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) Consortium provided data from up to 52,684 participants of European descent without known diabetes. In fixed-effects meta-analyses, we quantified 1) cross-sectional associations of dietary magnesium intake with fasting glucose (mmol/L) and insulin (ln-pmol/L) and 2) interactions between magnesium intake and SNPs related to fasting glucose (16 SNPs), insulin (2 SNPs), or magnesium (8 SNPs) on fasting glucose and insulin. After adjustment for age, sex, energy intake, BMI, and behavioral risk factors, magnesium (per 50-mg/d increment) was inversely associated with fasting glucose [β = -0.009 mmol/L (95% CI: -0.013, -0.005), P < 0.0001] and insulin [-0.020 ln-pmol/L (95% CI: -0.024, -0.017), P < 0.0001]. No magnesium-related SNP or interaction between any SNP and magnesium reached significance after correction for multiple testing. However, rs2274924 in magnesium transporter-encoding TRPM6 showed a nominal association (uncorrected P = 0.03) with glucose, and rs11558471 in SLC30A8 and rs3740393 near CNNM2 showed a nominal interaction (uncorrected, both P = 0.02) with magnesium on glucose. Consistent with other studies, a higher magnesium intake was associated with lower fasting glucose and insulin. Nominal evidence of TRPM6 influence and magnesium interaction with select loci suggests that further investigation is warranted.

Low serum magnesium level is associated with microalbuminuria in chinese diabetic patients

Whether serum magnesium deficiency is independently associated with the prevalence of microalbuminuria is still unclear. The objective of the present study was to elucidate the association between serum magnesium and microalbuminuria in diabetic patients. A cross-sectional study was conducted in 1829 diabetic subjects (aged ≥ 40 years) from Shanghai, China. Subjects were divided into three groups according to serum magnesium tertiles. A first-voided early-morning spot urine sample was obtained for urinary albumin-creatinine ratio (UACR) measurement. Microalbuminuria was defined as 30 mg/g ≤ UACR < 300 mg/g. Overall, 208 (11.37%) of the study population had microalbuminuria, with similar proportions in both genders (P = 0.44). The prevalence of microalbuminuria in tertile 1 of serum magnesium was higher than the prevalence in tertile 2 and tertile 3 (15.98%, 9.72%, and 8.46%, resp.; P for trend <0.0001). After adjustment for age, sex, BMI, blood pressure, lipidaemic profile, HbA1c, eGFR, history of cardiovascular disease, HOMA-IR, antihypertensive and antidiabetic medication, and diabetes duration, we found that, compared with the subjects in tertile 3 of serum magnesium, those in tertile 1 had 1.85 times more likeliness to have microalbuminuria. We concluded that low serum magnesium level was significantly associated with the prevalence of microalbuminuria in middle-aged and elderly Chinese.

Hypomagnesemia in type 2 diabetes mellitus

INTRODUCTION

Hypomagnesemia is reported in type 2 diabetes; magnesium deficiency may play a role in the development of endothelial dysfunction and altered insulin function.

OBJECTIVE

To assess the incidence of hypomagnesemia among noncritically ill patients of Type 2 diabetes mellitus and to evaluate the relation of hypomagnesemia to glycemic control and various long-term complications of diabetes mellitus.

MATERIALS AND METHODS

One hundred and fifty, noncritically ill (APACHE score < 10) type 2 diabetes mellitus patients, who were admitted in the Departments of Medicine and Endocrinology, GMCH for uncontrolled hyperglycemia and/or various diabetic complications were studied. Serum magnesium was assessed at admission and rechecked in those found to be deficient.

RESULTS

Hypomagnesemia (Se magnesium < 1.6 mg/dl) was documented in 17 (11.33%) patients with a female:male ratio of 9:8. Mean HbA1c was 11.9% in the hypomagnesemic patients compared with 9.8% in controls (P =0.0016). Retinopathy, microalbuminuria, macroalbuminuria, foot ulceration, and neuropathy was present in 64%, 47%, 17.64%, 58.8%, and 82.35%, respectively, of the patients with hypomagnesemia as compared with 45.8% (P =0.118), 38.34% (P =0.704),15.03% (P =0.566), 22.55% (P =0.011) and 82.7% (P =0.976) without hypomagnesemia. Coronary artery disease was less common in the hypomagnesemia group (17.6% vs 39%), but comparable in the subgroup < 50 years (27% vs 25%) (P =0.796).

CONCLUSION

Hypomagnesemia in diabetes was associated with poorer glycemic control, retinopathy, nephropathy, and foot ulcers.

Magnesium and its transporters in cancer: a novel paradigm in tumour development

The relationship between magnesium and cancer is not as simple as could be assumed from the well-established requirement of magnesium for cell proliferation. Basic and pre-clinical studies indicate that magnesium deficiency can have both anti- and pro-tumour effects. In the present review, we briefly outline the new findings on the role of magnesium in angiogenesis and metastatization, and focus on the relationship between tumour cell proliferation and metabolic reprogramming, discussing how magnesium and its transporters are involved in these processes. The role of magnesium in cancer is also critically examined with regard to mitochondrial function, apoptosis and resistance to treatment. Finally, we bring together the latest experimental evidence indicating that alteration in the expression and/or activity of magnesium channels is a frequent finding in cancer cells and human tumour tissues examined to date, and we discuss the potential implications for developing novel diagnostic and therapeutic strategies.

Effects of oral magnesium supplementation on inflammatory markers in middle-aged overweight women

BACKGROUND

This study aimed to investigate whether magnesium supplementation might affect serum magnesium, high sensitive C-reactive protein (hs-CRP), plasma fibrinogen, and interleukin 6 (IL-6) levels in healthy middle-aged overweight women. The relationships, if any, between serum magnesium and the inflammatory markers were also examined cross-sectionally in the entire participants at the beginning of the study.

MATERIALS AND METHODS

This double-blinded, placebo-controlled, randomized trial included 74 middle-aged overweight women. Participants were randomly assigned to receive either 250 mg magnesium as magnesium oxide or placebo daily for 8 weeks. Serum magnesium, hs-CRP, fibrinogen and IL-6 concentrations were measured before and after the intervention.

RESULTS

Serum magnesium was found to be inversely correlated with hs-CRP (rs =-0.22, P=0.05) in the entire participants at baseline. Serum hs-CRP declined significantly in both groups as compared with baseline values (median change=0.8 mg/L; PMagnesium= 0.03, PPlacebo < 0.001). Plasma fibrinogen decreased significantly, by 9%, in the magnesium group at the end of week 8 compared to baseline (P=0.001). Mean concentration of IL-6 was significantly increased in the magnesium group comparing the baseline value(P=0.001). However hs-CRP, fibrinogen and IL-6 levels at week 8 or any changes during the study were not statistically different between the two groups. Serum magnesium showed no significant changes in any groups.

CONCLUSIONS

Serum magnesium had a significant inverse correlation with hs-CRP. In the present study, magnesium as magnesium oxide, 250 mg/day, for 8 weeks did not significantly attenuate inflammatory markers in the magnesium group as compared to the placebo.

Natural polypill Xuezhikang: its clinical benefit and potential multicomponent synergistic mechanisms of action in cardiovascular disease and other chronic conditions

Polypill has been a hot issue since it was first advanced in 2003. This new concept immediately spurred a worldwide discussion. Xuezhikang is a partially purified extract of fermented red yeast rice (Monascus purpureus). It is composed of 13 kinds of natural statins, unsaturated fatty acids, ergosterol, amino acids, flavonoids, alkaloid, trace element, and other substances, and thus could be regarded as a natural lipid-lowering polypill. Interestingly, Xuezhikang in the China Coronary Secondary Prevention Study trial lowered lipid levels less as compared with provastatin in the Cholesterol and Recurrent Events trial, but seemed to gain more benefit in reducing the cardiovascular events and the risk of death from cancer. In recent years, Xuezhikang has been further demonstrated to have additional health benefits and thus raised great interest. This article reviews the clinical benefits of Xuezhikang and the potential multicomponent synergetic mechanism. The authors hold that polypill is anticipated to be a more effective and feasible way to treat complicated diseases.

Relationship between serum calcium and magnesium concentrations and metabolic syndrome diagnostic components in middle-aged Korean men

It is thought that calcium and magnesium may be related to metabolic disorders such as obesity and metabolic syndrome; however, to date, there have been few studies investigating the association between serum calcium and magnesium levels and metabolic syndrome in middle-aged male adults. We aimed to investigate the association between serum calcium and magnesium levels and metabolic syndrome in Korean middle-aged male adults. Study subjects included 213 men aged 30∼60 years. MetS risk score is determined by adding the number of risk factors, waist circumference, triacylglyceride (TG), HDL cholesterol, glucose, and blood pressure (BP). The study population was divided into three groups according to the MetS risk score: group I (MetS risk score ≤1; n = 106), group II (MetS risk score = 2; n = 51), and group III (MetS risk score ≥3; n = 56). The serum Ca, according to increase of MetS risk score, was significantly higher (p < 0.001), and there was no significant difference in serum Mg concentration among the three groups. Subjects with high TG and high BP had higher serum calcium levels than those without such abnormalities. Subjects with higher glucose had lower serum magnesium levels than those without such abnormality. The correlation analysis indicated that the serum Ca had positive correlations with the MetS risk score (r = 0.1769, p < 0.01), serum TG (r = 0.2516, p < 0.001), and DBP (r = 0.2246, p < 0.01). The correlation analysis indicated that the serum Mg had an inverse relationship with serum glucose (r = -0.2404, p < 0.001). In conclusion, serum Ca had positive association with TG and BP, while serum Mg had negative association with serum glucose after adjusting age and BMI among the middle-aged Korean male adults.

Endothelial cells and magnesium: implications in atherosclerosis

There is no doubt that the functional and structural integrity of the endothelium is critical in maintaining vascular homoeostasis and in preventing atherosclerosis. In the light of epidemiological and experimental studies, magnesium deficiency is emerging as an inducer of endothelial dysfunction. In particular, data on the effects of low extracellular magnesium on cultured endothelial cells reinforce the idea that correcting magnesium homoeostasis might be a helpful and inexpensive intervention to prevent and treat endothelial dysfunction and, consequently, atherosclerosis.

Suboptimal magnesium status in the United States: are the health consequences underestimated?

In comparison with calcium, magnesium is an "orphan nutrient" that has been studied considerably less heavily. Low magnesium intakes and blood levels have been associated with type 2 diabetes, metabolic syndrome, elevated C-reactive protein, hypertension, atherosclerotic vascular disease, sudden cardiac death, osteoporosis, migraine headache, asthma, and colon cancer. Almost half (48%) of the US population consumed less than the required amount of magnesium from food in 2005-2006, and the figure was down from 56% in 2001-2002. Surveys conducted over 30 years indicate rising calcium-to-magnesium food-intake ratios among adults and the elderly in the United States, excluding intake from supplements, which favor calcium over magnesium. The prevalence and incidence of type 2 diabetes in the United States increased sharply between 1994 and 2001 as the ratio of calcium-to-magnesium intake from food rose from <3.0 to >3.0. Dietary Reference Intakes determined by balance studies may be misleading if subjects have chronic latent magnesium deficiency but are assumed to be healthy. Cellular magnesium deficit, perhaps involving TRPM6/7 channels, elicits calcium-activated inflammatory cascades independent of injury or pathogens. Refining the magnesium requirements and understanding how low magnesium status and rising calcium-to-magnesium ratios influence the incidence of type 2 diabetes, metabolic syndrome, osteoporosis, and other inflammation-related disorders are research priorities.